"These mosquitoes don't breed in the pools and puddles that you would normally expect mosquitoes to be breeding in up on the surface," says Webb. "Their immature stage is exclusively underground."

When a typical water-dwelling mosquito larvae changes into an adult female, it needs a protein hit before it is able to develop eggs, says Webb.

"Before they're able to lay their first batch of eggs they need to have a blood meal," he says.

But Culex molestus is an exception, postponing its first blood meal and instead relying on its existing nutrient stores to produce eggs.

Webb and colleagues explored how this behaviour might have helped it adapt to breeding underground.

The mosquito is commonly referred to as the London Underground mosquito because it fed on Londoners sleeping in the Underground during the Blitz in World War II. It was believed to have hitched a ride to Australia on American soldiers during the 1940s.